Exhaust manifold



y 21, 1929- G. M. BELLANCA- 1,713,814,

EXHAUST MANIFOLD Filed Sept. 16. 1926 2 Sheets-Sheet l W 1 .9 119239. M.EELLANQA L M EXHAUST MANIFOLD Filed Sept. 16, 1926 2 Sheets-Sheet 2 IN VEN TOR.

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A TTORNEYJL GUISEPTJE MAE-3T0 BELLANCA, 0F PASSAIC, NEW JERSEY.

nxnaus'r MANIFOLD.

Application filed September 16, 1926. Serial No. 135,770.

This invention relates to the construction and mounting of an exhaust manifold for aeronautical engines.

In the development of airplanes in connection with which engines of the radial and other more .or less similar types are used, considerable d ii'liculty has been found in so mounting the exhaust manifold that it will not present a substantial surface area to produce air resistance and a corresponding restriction in speed of flight of the airplane. This diiiiculty arises out of the necessity for mounting the exhaust manifold Outside, the chamber formed by the shell of the fuselage and in a disposition substantially encircling the cowl portion of the fuselage transversely to the direction of flight. The manifold-,- by thus extending across the line of flight, presents its forward surface throughout its length to the resistance of the air.

A general object of the present invention is'to provide an exhaust manifold for radial aeronautical engines which will be free from the objectionable features referred to and which will provide a minimum amount of air resistance.

Further objects of the invention are to minimize the efl'ects of the noise produced by the discharging exhaust, to prevent overheating of the manifold, and to prevent buckling V v or distortion of the parts under expansion exhaust manifold in effects arising out of temperature changes.

. The invention includes the mounting of the a recess or channel formed in the surface of the engine cowling, the manifold being thereby partly or wholly protected from engagement of the rushing a'ir therewith.

Anotherfeature of the invention is themounting of the manifold in a spaced apart relation to the surface of the receiving'channel so that air can flow through the space between the manifold and channel surface toproduce a cooling effect on the manifold and prevent overheating thereof.

Another feature of the invention resides in the provision of an exhaust manifold having a formation in cross-section such-as will provide a minimum air-resistance area.

Another feature of the invention resides in the use of flexible joints in the manifold structure to prevent injury to the parts by expansion and contraction eflects.

Still another feature of the invention re sides in an adaptability of the manifold structure to be mounted in various positions tocause the exhaustto be discharged at any desired point in the length of the manifold structure.

Other features of the invention will be hereinafter referred to.

In the drawings, in which a preferred embodiment of-the invention has been selected for illustration,

Figure l is a diagrammatic view showing a portion of the forward end of an airplane equipped with an exhaust manifold construction embodying the invention.

Figure 2 is a sectional view on an enlarged scale taken on the line 22 of Figure 1.

Figure 3 is a detail view in perspective showing a flexible joint construction forming part of the invention.

the. manifold structure detached from the engine cowling and presenting arearward' view thereof. v Figure 6 is a sectional view of a modification of Figure 2. p

Referring to the drawings for a more detailed description of;-the invention, at 10 is shown the engine cowling portion of the fuselage of an airplane through openings 11 in which the cylinders 12 of an engine of the radial type protrude. The forward portion of the cowling 10 is equipped with a cap member or fairing 13 designed todecrea'se' the effectof air resistance acting on the hub portions of the propeller 14-. In order to dispose of the exhaust from the radially disposed cylinders12 through a common discharge conduit an exhaust manifold 15 is made use of which is disposed in a substantially encircling relation to'the cowl structure 10, the location of the manifold being the engine cylinders-12.. Branch pipe connectlons 16 are provided between the exhaust discharge ports 17 of the engine cylinders 12 and the manifold 15, the manifold terminating in a discharge member 18 which is directed rearwardly and may be extended for any desired distance along an outer wall of the fuselage.

In order to cause the manifold to present a minimum area of surface to prevent air re sistance the manifold is mounted in a recess orgroove'19g formed in the outer surface of the engine cowling 10., The groove or recess 19 extends circumferentially around the enjust to the rear of the "posit-ions of tion to the cowl so as tire surface of the cowl and this disposition of the groove provides for the mounting of the manifold in any desired angular relato cause the discharge member 18 to be located at the most convenient point. In Figure 1 of the drawing the 1 discharge member 18 ofthe manifold is shown disposed beneath the'floor wall of the adjacent surface of thecowl 10,'the manifold is so mounted as to be slightly spaced apart from the adjacent surface of the groove or recess 19 as is clearly shown in Figures 1 and 2 of the drawings. The space 20 which is thus formed provides a passageway through which air can flow, as is indicated by the arrows in Figure 2 of the drawings, to thereby dissipate heat and prevent overheating of the adjacent parts. In order to facilitate the rush of air through the passageway 20 formed between the manifold .15 and the surface of the groove 19 the forwarder leading edge 21 of the manifold is caused to protrude slightly beyond the adjacent outer surface of the cowl 10 to thereby function to provide a scooping action on the air stream rushing rearwardly along the surface of the cowl 10. The air thus caught or entrapped is diverted through the channel 20 as will be seen and cooling efiect referred to.

It will also be noted that the cross-section or formation of the manifold member 15 is such as to'present a minimum degree ofr'esistance tothe air. In the drawings it will be noted that the manifold has the formation of a fiattened tube with forwardly and rearwardly extending angles and a substantially flat outer surface following approximately the contour of the outer surface of the cowl 10. While this particular formation has been found effective in practice it w1ll be apparent that other formations of the manifold cross-section may be employed with usefulresults. v

Another the use of flexible or yielding coupling elements in the body structure of themanifold member and also in the branch pipes 16 through which connections are made between the manifold Coupling members or joints 22 are provided in the branch pipe connections 16 for this purpose. These coupling members may take the form of splitsleeves an. exam le of which is shown in Figure 1 of the drawings, the sleeve produces the the terminal discharging mem-- feature of the invention resides in and the engine cylinders 12;

iniaeia being provided with a clamping bolt- 23 and having suitable corrugations 24 to prevent slipping of the coupling member from engagement with the joint sections of the branch exhaust pipes 16.

In order to provide for expansion or contraction of the manifold structure itself under changing temperature conditions a telescopic joint 25 is provided which permits of relative movement of the contiguous sections of the manifold toward or from each other to thereby prevent distortion or other injury to the manifold by the expansion and contraction effects due to changes in temperature.

In certain types of construction it is possible that the addition of the exhaust manifold of my invention may interfere with the application and removal of the material of the cowl structure. To obviate this difliculty the construction indicated in Figure 6 may be used. In thisembodiment the cowl 10 of Figures 1 and 2 may be cut into portions. For instance, a nose portion 26 may be provided, cooperatingwith a recess portion 27, in the recess of which the exhaust manifold 21 may be positioned. The manifold may be spaced away from the member 27 by a small distance as beforeto provide the passageway 20 for cooling air. This construction permits the ready removal of the nose, portion of the cowl for access to the engine members,

or of the rear portion, or ofthe manifold and grooved portion together.

As a further modification the cowl member may be separated at two points as shown in Figure 6 to providea nose portion 26, a channel portion 27 and a rear portion 28. This construction permits the removal of the nose portion and the rear portion of the cowl independently of the exhaust manifold and of the recess portion. This modification of the construction provides means for a more convenient and easy access to the engine struc V tures. i

It will be seen that a manifold structure and a methodof mounting been provided which overcomes or obviates the air resistance effects which are ordinarily encountered in the use of a manifold structure which must be disposed transversely to the lineof flight of the airplane on which it is carried.--

The language and expressions hich have been employed throughout-the specification are used as terms of description only and not of limitation, and such terms are intended to include all the equivalents-and such modifications as are possible the scope of the invention claimed.

What I claim is 1. In an exhaust manifold construction for aeronautical engines of the radial type, a cowl through which the exhaust discharging ends of the radially disposed cylinders project, said cowl being provided with a circumthe same have to be employed within scribing groove in its outer surface adjacent the engine cylinders, an exhaust manifold mounted in said groove and adjustable cireumferentially therein, and a dischargeterminal on the exhaust manifold.

2. In anexhaust manifold construction for aeronautical engines of the radial type, a cowl through which the exhaust discharging ends of the radially disposed cylinders project, an exhaust manifold for'said cylinders mounted in circumscribing relation to the cowl, and said manifold being formed with flattened cross-section with its edges arranged fore and aft to present a minimum degree of air resistance. i

3. In an exhaust manifold construction for aeronautical engines of the radial type, a cowl through-which the exhaust discharging ends of the radially disposed cylinders of the engine project, an exhaust manifold for said cylinders mounted in circimiscribing relation to the cowl, branch-pipe connections between the cylinders and the manifold, and flexible joint sections contained in said branch pi-pe connections.

4. In an exhaust manifold construction for aeronauticalengines of the radial type, an exhaust manifold for the engine cylinders mounted in an encircling disposition with relation to the longitudinal axis of the airplane, said manifold being circumferentially adj ustable to vary the position of thedischarge terminal, a yielding joint connection in said manifold whereby to provide for expansion and contraction effects, and said manifold having a flattened.cross-sectional formation designed to present a minimum of air resistance.

5. In an exhaust manifold construction for aeronautical engines of the radial type, a cowl through which the exhaust discharging ends of the radially disposed cylinders project, said cowl being provided with a circumscribing groove in its outer surface adjacent the engine cylinders, an exhaust manifold mounted in said grocive, said manifold being circumferentially adjustable in said groove and spaced from the Walls of the groove to permit a cur-. rent of air to pass therethrough, aflexible joint in said manifold, branch pipe connections between said cylinders and said manifold, and flexible joint sections in said branch connections.

6. In an exhaust manifold construction for aeronautical engines, a cowl for the engine in and extending alongsaid groove, said manifolddiaving its underside formed in complement to the formation of the surface of the groove but spaced therefrom, the outer surface of the manifold being substantially. flat andconforming approximately to theformation ofthe cowl surface, and the forward edge of'the manifold protruding slightly beyond the contour of the cowl surface whereby to deflect air throughthe space between the manifold and the surface of the groove.

7. In an exhaust manifold construction for aeronautical engines of the radial type, a cowl through which the exhaust discharging ends of the radially disposed cylinders project, said cowl being provided with a circumscribing groove in its outer surface adpj zvided with a circumferential groove in its outer surface, an exhaust manifold mounted jacent the engine cylinders, said cowl coini prising separable portions, wherebya part theredf may he removed independently of said exhaust members, an exhaust manifold mounted in said groove, said manifold being circumferentially adjustable in said groove 'and spaced from the walls of the groove to permit a, current of air to pass therethrough,

.a flexible joint in said manifold, branch pipe eni snrrn M. BELLANCA. 

